(1) Field of the Invention
The present invention pertains to a ballistic projectile resistant barrier with improved ballistic projectile resistance. The barrier is lightweight and can be worn as a garment or draped over an object to provide ballistic projectile protection to stationary or mobile entities, military or civilian.
(2) Description of the Related Art
In the early development of ballistic projectile barriers such as flak jackets or vehicle armor, it was a commonly agreed upon theory that the barrier must be at least as hard, or harder than the ballistic projectile to be stopped. It was necessary that the barrier be very strong with a high degree of structural integrity so that impact of the projectile with the barrier would deform the projectile into a flattened shape, thereby transferring the kinetic energy of the projectile into a larger surface area. This would allow the barrier to absorb the impact energy of the projectile while preventing penetration of the barrier. The levels of barrier thickness and hardness were adjusted in designing barriers that were impenetrable to various ballistic threats.
Another commonly accepted theory in the development of ballistic projectile barriers relies on multiple layers or laminates of a flexible material in constructing the barrier. The multiple material layers allow a degree of movement of each layer in the barrier. The movement allows a degree of stretching to occur when a layer is impacted by a projectile, which takes advantage of the material tensile strength and transfers some energy of the impact into each layer of material. The kinetic energy of the impacting projectile is more effectively spread into a larger surface area through the thickness of the barrier, with the surface area increasing on each consecutive material layer of the barrier.
Materials commonly used in laminate barriers are made of woven aramid fibers that are saturated and bonded with a matrix of thermosetting plastic resin. This produces a barrier that very effectively takes advantage of the high tensile strength of the aramid fibers.
The prior art ballistic projectile barriers that employ hard materials such as ballistic steel are disadvantaged in that they are very heavy. In high mobility applications, for example in flak jackets worn by soldiers, the increased weight of the ballistic barrier is a significant disadvantage. In addition, with the complex designs used in ballistic barriers today, the use of ballistic steel is further disadvantaged in that it is not easily fabricated.
Ceramic barriers are less dense than steel and therefore weigh less per thickness of the barrier than steel. Ceramic materials can also be produced with extremely high levels of hardness. Thus, the ceramic materials have many advantages over ballistic steel, but are very expensive and are also very difficult to fabricate in many applications.
Laminate barriers using woven layers of aramid fibers are manufactured using very complex methods. These methods of manufacture are time consuming and, in addition to the materials used, can be very expensive. Laminate barriers are most disadvantaged by their lack of hardness and their susceptibility to penetration by armor-piercing projectiles.